httpauth: make multi-request auth work with custom portbagder/multi-stage-auth-custom-port

When doing HTTP authentication and a port number set with CURLOPT_PORT,
the code would previously have the URL's port number override as if it
had been a redirect to an absolute URL.

Added test 1568 to verify.

Reported-by: UrsusArctos on github
Fixes #6397

8 files changed, 160 insertions, 15 deletions

diff --git a/lib/multi.c b/lib/multi.c
index bf439bb8e..d3863c1e9 100644
--- a/lib/multi.c
+++ b/lib/multi.c
@@ -5,7 +5,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2021, Daniel Stenberg, <daniel@haxx.se>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
@@ -2211,7 +2211,6 @@ static CURLMcode multi_runsingle(struct Curl_multi *multi,
         multi_done(data, result, TRUE);
       }
       else if(done) {
-        followtype follow = FOLLOW_NONE;
 
         /* call this even if the readwrite function returned error */
         Curl_posttransfer(data);
@@ -2219,6 +2218,7 @@ static CURLMcode multi_runsingle(struct Curl_multi *multi,
         /* When we follow redirects or is set to retry the connection, we must
            to go back to the CONNECT state */
         if(data->req.newurl || retry) {
+          followtype follow = FOLLOW_NONE;
           if(!retry) {
             /* if the URL is a follow-location and not just a retried request
                then figure out the URL here */
diff --git a/lib/transfer.c b/lib/transfer.c
index a2a890ecf..345ff1cdd 100644
--- a/lib/transfer.c
+++ b/lib/transfer.c
@@ -5,7 +5,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2021, Daniel Stenberg, <daniel@haxx.se>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
@@ -1537,6 +1537,8 @@ CURLcode Curl_follow(struct Curl_easy *data,
   bool reachedmax = FALSE;
   CURLUcode uc;
 
+  DEBUGASSERT(type != FOLLOW_NONE);
+
   if(type == FOLLOW_REDIR) {
     if((data->set.maxredirs != -1) &&
        (data->set.followlocation >= data->set.maxredirs)) {
@@ -1568,8 +1570,11 @@ CURLcode Curl_follow(struct Curl_easy *data,
     }
   }
 
-  if(Curl_is_absolute_url(newurl, NULL, MAX_SCHEME_LEN))
-    /* This is an absolute URL, don't allow the custom port number */
+  if((type != FOLLOW_RETRY) &&
+     (data->req.httpcode != 401) && (data->req.httpcode != 407) &&
+     Curl_is_absolute_url(newurl, NULL, MAX_SCHEME_LEN))
+    /* If this is not redirect due to a 401 or 407 response and an absolute
+       URL: don't allow a custom port number */
     disallowport = TRUE;
 
   DEBUGASSERT(data->state.uh);
diff --git a/lib/transfer.h b/lib/transfer.h
index 178bb58fb..f8915dbd1 100644
--- a/lib/transfer.h
+++ b/lib/transfer.h
@@ -7,7 +7,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2021, Daniel Stenberg, <daniel@haxx.se>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
@@ -36,9 +36,8 @@ typedef enum {
                    allow initing to this */
   FOLLOW_FAKE,  /* only records stuff, not actually following */
   FOLLOW_RETRY, /* set if this is a request retry as opposed to a real
-                          redirect following */
-  FOLLOW_REDIR, /* a full true redirect */
-  FOLLOW_LAST   /* never used */
+                   redirect following */
+  FOLLOW_REDIR /* a full true redirect */
 } followtype;
 
 CURLcode Curl_follow(struct Curl_easy *data, char *newurl,
diff --git a/lib/url.c b/lib/url.c
index d86d8b0b6..cf68bc29d 100644
--- a/lib/url.c
+++ b/lib/url.c
@@ -5,7 +5,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2021, Daniel Stenberg, <daniel@haxx.se>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
@@ -2003,7 +2003,9 @@ static CURLcode parseurlandfillconn(struct Curl_easy *data,
   }
   else {
     unsigned long port = strtoul(data->state.up.port, NULL, 10);
-    conn->port = conn->remote_port = curlx_ultous(port);
+    conn->port = conn->remote_port =
+      (data->set.use_port && data->state.allow_port) ?
+      (int)data->set.use_port : curlx_ultous(port);
   }
 
   (void)curl_url_get(uh, CURLUPART_QUERY, &data->state.up.query, 0);
diff --git a/tests/data/Makefile.inc b/tests/data/Makefile.inc
index 4b9fc44dc..6aa871bbf 100644
--- a/tests/data/Makefile.inc
+++ b/tests/data/Makefile.inc
@@ -5,7 +5,7 @@
 #                            | (__| |_| |  _ <| |___
 #                             \___|\___/|_| \_\_____|
 #
-# Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al.
+# Copyright (C) 1998 - 2021, Daniel Stenberg, <daniel@haxx.se>, et al.
 #
 # This software is licensed as described in the file COPYING, which
 # you should have received as part of this distribution. The terms
@@ -187,7 +187,7 @@ test1540 \
 \
 test1550 test1551 test1552 test1553 test1554 test1555 test1556 test1557 \
 test1558 test1559 test1560 test1561 test1562 test1563 test1564 test1565 \
-test1566 test1567 \
+test1566 test1567 test1568 \
 \
 test1590 test1591 test1592 test1593 test1594 test1595 test1596 \
 \
diff --git a/tests/data/test1568 b/tests/data/test1568
new file mode 100644
index 000000000..62d1132eb
--- /dev/null
+++ b/tests/data/test1568
@@ -0,0 +1,87 @@
+<testcase>
+# based on test 64
+
+<info>
+<keywords>
+HTTP
+HTTP GET
+HTTP Digest auth
+</keywords>
+</info>
+
+<reply>
+<data>
+HTTP/1.1 401 Authorization Required swsclose

+Server: Apache/1.3.27 (Darwin) PHP/4.1.2

+WWW-Authenticate: Digest realm="testrealm", nonce="1053604145"

+Content-Type: text/html; charset=iso-8859-1

+Content-Length: 26

+

+This is not the real page
+</data>
+
+# This is supposed to be returned when the server gets a
+# Authorization: Digest line passed-in from the client
+<data1000>
+HTTP/1.1 200 OK swsclose

+Server: Apache/1.3.27 (Darwin) PHP/4.1.2

+Content-Type: text/html; charset=iso-8859-1

+Content-Length: 23

+

+This IS the real page!
+</data1000>
+
+<datacheck>
+HTTP/1.1 401 Authorization Required swsclose

+Server: Apache/1.3.27 (Darwin) PHP/4.1.2

+WWW-Authenticate: Digest realm="testrealm", nonce="1053604145"

+Content-Type: text/html; charset=iso-8859-1

+Content-Length: 26

+

+HTTP/1.1 200 OK swsclose

+Server: Apache/1.3.27 (Darwin) PHP/4.1.2

+Content-Type: text/html; charset=iso-8859-1

+Content-Length: 23

+

+This IS the real page!
+</datacheck>
+
+</reply>
+
+# Client-side
+<client>
+<server>
+http
+</server>
+<features>
+!SSPI
+crypto
+</features>
+<name>
+HTTP with Digest authorization on custom CURLOPT_PORT
+</name>
+<tool>
+lib1568
+</tool>
+<command>
+http://%HOSTIP/1568 %HTTPPORT
+</command>
+</client>
+
+# Verify data after the test has been "shot"
+<verify>
+<protocol>
+GET /1568 HTTP/1.1

+Host: %HOSTIP:%HTTPPORT

+User-Agent: lib1568

+Accept: */*

+

+GET /1568 HTTP/1.1

+Host: %HOSTIP:%HTTPPORT

+Authorization: Digest username="testuser", realm="testrealm", nonce="1053604145", uri="/1568", response="9cbbd857a37e45f2bcad5c7d088191df"

+User-Agent: lib1568

+Accept: */*

+

+</protocol>
+</verify>
+</testcase>
diff --git a/tests/libtest/Makefile.inc b/tests/libtest/Makefile.inc
index 9496bd074..28cf92ab7 100644
--- a/tests/libtest/Makefile.inc
+++ b/tests/libtest/Makefile.inc
@@ -5,7 +5,7 @@
 #                            | (__| |_| |  _ <| |___
 #                             \___|\___/|_| \_\_____|
 #
-# Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al.
+# Copyright (C) 1998 - 2021, Daniel Stenberg, <daniel@haxx.se>, et al.
 #
 # This software is licensed as described in the file COPYING, which
 # you should have received as part of this distribution. The terms
@@ -56,7 +56,7 @@ noinst_PROGRAMS = chkhostname libauthretry libntlmconnect                \
  lib1534 lib1535 lib1536 lib1537 lib1538 lib1539 \
  lib1540         \
  lib1550 lib1551 lib1552 lib1553 lib1554 lib1555 lib1556 lib1557 \
- lib1558 lib1559 lib1560 lib1564 lib1565 lib1567 \
+ lib1558 lib1559 lib1560 lib1564 lib1565 lib1567 lib1568 \
  lib1591 lib1592 lib1593 lib1594 lib1596 \
          lib1905 lib1906 lib1907 lib1908 lib1910 lib1911 lib1912 lib1913 \
          lib1915 lib1916 lib1917 lib1933 \
@@ -601,6 +601,9 @@ lib1565_CPPFLAGS = $(AM_CPPFLAGS)
 lib1567_SOURCES = lib1567.c $(SUPPORTFILES)
 lib1567_CPPFLAGS = $(AM_CPPFLAGS)
 
+lib1568_SOURCES = lib1568.c $(SUPPORTFILES)
+lib1568_CPPFLAGS = $(AM_CPPFLAGS)
+
 lib1591_SOURCES = lib1591.c $(SUPPORTFILES) $(TESTUTIL) $(WARNLESS)
 lib1591_LDADD = $(TESTUTIL_LIBS)
 lib1591_CPPFLAGS = $(AM_CPPFLAGS) -DLIB1591
diff --git a/tests/libtest/lib1568.c b/tests/libtest/lib1568.c
new file mode 100644
index 000000000..2e5d88c70
--- /dev/null
+++ b/tests/libtest/lib1568.c
@@ -0,0 +1,49 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 2021, Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at https://curl.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+#include "test.h"
+
+#include "testtrace.h"
+#include "memdebug.h"
+
+int test(char *URL)
+{
+  CURLcode ret;
+  CURL *hnd;
+
+  hnd = curl_easy_init();
+  curl_easy_setopt(hnd, CURLOPT_URL, URL);
+  curl_easy_setopt(hnd, CURLOPT_VERBOSE, 1L);
+  curl_easy_setopt(hnd, CURLOPT_HEADER, 1L);
+  curl_easy_setopt(hnd, CURLOPT_USERPWD, "testuser:testpass");
+  curl_easy_setopt(hnd, CURLOPT_USERAGENT, "lib1568");
+  curl_easy_setopt(hnd, CURLOPT_HTTPAUTH, (long)CURLAUTH_DIGEST);
+  curl_easy_setopt(hnd, CURLOPT_MAXREDIRS, 50L);
+  curl_easy_setopt(hnd, CURLOPT_PORT, (long)atoi(libtest_arg2));
+
+  ret = curl_easy_perform(hnd);
+
+  curl_easy_cleanup(hnd);
+  hnd = NULL;
+
+  return (int)ret;
+}
+